Simulation of surface acoustic wave sensors

D.W. Greve
DWGreve Consulting Email:

SAW devices with a chemical-sensing overlayer provide for the selective sensing of particular gases. Sensing takes place due to electrical conductivity and mass density changes of the overlayer that change the propagation velocity of acoustic surface waves.

This model evaluates the change in eigenfrequency corresponding to a surface acoustic wave of a particular wavelength due to a conductive overlayer. The change in eigenfrequency is directly related to the change in velocity through c = f*lambda, where lambda is the wavelength.

Two models are attached. The first finds the eigenmodes corresponding to a surface wave propagating on a YZ-LiNbO3 substrate without a sensing layer. The second determines the effect of an overlayer of varying conductivity.

In this webinar, we will show how the COMSOL Multiphysics® software supports the design of SAW sensors by simulating the changes in the acoustic surface wave velocity due to changes in the overlayer. You will see a live demonstration of how to perform an eigenfrequency analysis of surface wave modes and derive the acoustic wave velocity, including how to specify model settings such as boundary conditions and material properties.